encourages discussions about developing sustainable systems to help alleviate problems based in urban environments. >> tell me what have you guys built? what is it? >> it's a big -- it's an integrated lawn. >> what kinds of plants did you plant in yours? >> lettuce, basil, and carrots. >> this is something i could grow on my roof? >> yeah. >> if you want -- if you went to your landlord and asked him, can i grow some plants on the roof and he said sure, it's easier to get your food from a local place, and it's healthier and -- >> you're harvesting, do you select a large plant? >> with the help of the students, this particular greenhouse can produce up to 9,000 pounds of produce a year. more than the kids could ever eat, so this class of second graders voted to donate their greens to meals on wheels. >> we appreciate it. >> which delivered the produce to a senior citizens senior in midtown manhattan. >> so one of the great things about all the produce that they produce here is that it's a great way to connect to the community. >> just like the students, many businesses are also experimenting with hy